baenaed



No Model.) i. 2 Sheets-sheet 1.

L.V E. HLL 8v H. L. BARNARD.

SPEIYGMOMANOMBTBR lmanned Peb. 1, 1898.

l2 Shepts-SlneL :2.

L. E. HILL 88 81.8888818813. SPHYGMOMANOMETER.

No. 588,848. Pate-m8681188. 1,1898.

(No Model.)

V UNITED STATES PATENT 'OEFicEQ LEONARD E; HILL AND 'HAROLD L.

- AssIGNoRs or ONE-THIRD To JAMES JOSEPH BARNARD, or LONDON, ENGLAND,

mens, or SAME PLACE.

f s .PHvcm'c-lvlANolvia-Tsn.

SPECIFICATION forming part'of Letters Patent lN o. 598,343, dated February 1, 1898. Lppncaitn mea July 9,1897. sam No. 643,951. (No moa-e1.)

du whom tmay concern:

Be it known that We, LEOXARD E. HILL and HAROLD L. BARNARD, subjects of the Queen of GreatBritain,residin g at London, England, have invented certain new and useful lmprovements i-n Sphygmomanometers,of which the following is a full, clear, and exact de',-

scription.

1 The invention yhas for its object improvel xo .nientsin sphyg'momanometers whereby not only the blood-pressure lin the arteries of man or animal but also the pulsations of the 'arterie's are clearly indicated on a scale', the meanv arterial vblood-pressure being indicated in our im'pzfbtfed instrument by the maximum Jof such- 'pulsatio'ns Our invention is illustrated in the accom-4 panyi gdrawingsjnwhich* Figure 1 isa view of the apparatus cornplete.. Fig. 2 is aside elevation, and Fig. 3 isa plan, ofthe manomet-er; and Fig. 4.- is a `section of part-ot the spring-clasp separately.

anjaneroid barometer, but'notb exhausted.

, positionwhen the Accord-ing to Vour invention We `employ a spring-'clasp a, /preferably of steel, covered With-india-rubber and lined with a laccid rubber bag b and made to partially or entirely encircle the arm or other part of the body. We :connect this rubber bag b by a tube c Wthan air-pump cl and With the tube e' of a inan'ometer having a chamber e like that of lSuch'chamber has pressing. on its outer side a spring f, which'is compressed by the pres-- sure of air within the chamber e and acts to .retnrnthe side of said chamber to its normal pressu're is relieved. This chamber operates a hand or pointer g by simianero'id barometer,

m,'ito which latter is alsoiixed a longer lever lar vmechanism to that used in an ordinary as hereinbei'ore described, and said hand or pointer g moves over a suitably-divided scale h'. 4

Tle chamber e is fixed to the foundation- -plate j, and it has fixedI to its upperV side an armxt, 4conmected by link Z with a small adjustable lever m', fixed on the pivoted shaft m2. This lever m2 is connected by link a and chainn with a pulley g? on the spindle g' of the hand or pointer g, and to such spindle g is attached one end of a spiral spring o, the other end of which isconnected to one of the pillars p of a frame arm p2, extending over the chamber e.

The tubed, attached to the pump d, is provided With a valve t' similarto that used With pneumatic tires, whereby the air-pressure can be gradually relieved When desired by slightly rotating the part z" until the maximum pulsa-l tion of the hand or pointer gis obtained, and itis also provided with an ordinary non-return valve to prevent lossof pressure except When the relief-valve is operated.

The mode of using the apparatus is asfollows: The spring-clasp a is. lightly fixed, say, around the arm. Pressure is then applied by means of the pump d until the' rubber bag b on the inside of the clasp applies suflicie'nt pressure on the arteries to give the maximum pulsation of the hand or pointer g and also to give the pressures atwhich the pulsation apv pears and disappears as the pressure is raised.

. Having fully described our invention, what We desire to claim and secure by Letters Patent is A sphygmomanometer, comprising, in co1n bination, a spring-clasp, a flexible air-bag on the inside of ,such clasp, an air-pump, a tube connecting such flexible 'bag pump and a manomet-er comprising a liexible chamber connected to said iiexible bag `anda pointer mechanically connected to theiiexfible chamber of the manometer so as @to be moved thereby -in response to the pressure, and pulsa-tion of pressure, on the flexible rubber bag.

In testimony whereof We affix tures in presence of two Witnesses. v

. LEONARD E. HILL. HAROLD L. BARNARD.

, lVitnesses:

E. J. B. MILLS, CLAUDE K. MILLS.

p, carried by the fixed with the air.

oursigna- 

